1. Field of the Invention
The present invention relates to a belt type continuous reduction gear mechanism in which a V-belt is made to run under tension between such drive and driven V-pulleys as are each equipped with a fixed pulley half and a movable pulley half made movable back and forth relative to the fixed half for adjustment of an effective radius.
2. Description of the Prior Art
In the continuous reduction gear mechanism of the aforementioned type according to the prior art, there has been widely adopted a one-side following system in which only the drive V-pulley is equipped with an actuator for moving the movable pulley half back and forth so that the forward and backward movements of the movable pulley half at the drive side may be transmitted during reduction through the V-belt to the movable pulley half at the driven side thereby to make the latter move back and forth. The one-side following system experiences disadvantageous phenomena such as deformation, heat generation or wear, because its V-belt is subjected to an excessive tension, so that the V-belt has not only its transmission efficiency remarkably deteriorated but also its lifetime shortened. That following system has another defect that the movable pulley half at the driven side has its following operation delayed to degrade the running performance of a vehicle having such particular system.